PHILADELPHIA - DHEA is a natural circulating hormone and the body's production of it decreases with age. Men take DHEA as an over-the-counter supplement because it has been suggested that DHEA can reverse aging or have anabolic effects since it can be metabolized in the body to androgens. Increased consumption of dietary isoflavones is associated with a decreased risk of prostate cancer. Red clover (Trifolium pretense) is one source of isoflavones. Both supplements may have hormonal effects in the prostate and little is known about the safety of these supplements.

In a recent report in Cancer Prevention Research, a journal of the American Association for Cancer Research, researchers report that DHEA levels can be manipulated in cells in the laboratory to understand its effects.

Julia Arnold, Ph.D., a staff scientist at the National Center for Complementary and Alternative Medicine (NCCAM) at the National Institutes of Health, said more research is necessary in an environment where men and women concerned about health problems tend to self-prescribe based on information they find on the Internet.

Towards this end, the NCCAM laboratory is studying signaling between human prostate cancer cells and their supporting stromal cells as they grow together in laboratory culture. "DHEA effects in the prostate tissues may depend on how these two cells types 'talk to each other' and further, it may be potentially harmful in tissues containing inflammation or with early cancer lesions because the cells can induce DHEA to become more androgenic," said Arnold.

Combining DHEA with transforming growth factor beta-1 increased testosterone production in the stromal cells and prostate specific antigen protein secretion two to four-fold and gene expression up to 50-fold in the cancer cells. When these cell cultures were treated with red clover isoflavones, the androgenic effects of DHEA were reversed.

"Something is happening in the prostate tissue microenvironment that is illustrating a potential cancer prevention effect from this supplement," said Arnold.

Red clover isoflavones may modify androgenic effects in the prostate but much more work in the laboratory and clinic is needed to validate these effects.

This sort of laboratory manipulation will allow scientists to understand the basic prostate biology as well as learn cellular and molecular mechanisms of over-the-counter supplements and other botanical or herbal agents. Arnold said NCCAM will continue to study DHEA with other supplements to determine any cancer preventive effects.

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The mission of the American Association for Cancer Research is to prevent and cure cancer. Founded in 1907, AACR is the world's oldest and largest professional organization dedicated to advancing cancer research. The membership includes more than 28,000 basic, translational and clinical researchers; health care professionals; and cancer survivors and advocates in the United States and 80 other countries. The AACR marshals the full spectrum of expertise from the cancer community to accelerate progress in the prevention, diagnosis and treatment of cancer through high-quality scientific and educational programs. It funds innovative, meritorious research grants. The AACR Annual Meeting attracts more than 17,000 participants who share the latest discoveries and developments in the field. Special conferences throughout the year present novel data across a wide variety of topics in cancer research, treatment and patient care. The AACR publishes five major peer-reviewed journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; and Cancer Epidemiology, Biomarkers & Prevention. The AACR's most recent publication and its sixth major journal, Cancer Prevention Research, is dedicated exclusively to cancer prevention, from preclinical research to clinical trials. The AACR also publishes CR, a magazine for cancer survivors and their families, patient advocates, physicians and scientists. CR provides a forum for sharing essential, evidence-based information and perspectives on progress in cancer research, survivorship and advocacy.

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